If anybody can tell you about the ins and outs of shoulder-bag design, it’s a mail carrier. Every day, these intrepid couriers get to haul around Lord knows how many pounds of real mail, junk mail, and those awful freebie newspapers that most of us toss into the recycling bin or use for lining the bottom of a bird cage.

Experienced photographers can also tell you a thing or two about shoulder bags. Speaking as a shooter who has purchased more bags than I want to admit (and I can justify purchasing all of them!) I can’t tell you how many times I found myself loving the bag but hating the strap.

Some straps are too narrow and cut into my shoulder, while others are made of materials that are so smooth they slide off my shoulder if I lean more than 5° off-center, which is something I do often when I’m out taking photographs. Some bags come with shoulder strap pads, but most are too thin, poorly padded, cheaply made, or they’re difficult to keep in place.

A few months ago I discovered a shoulder pad that has made it possible for me to reconsider shoulder bags with straps I had long given up as lost causes. Domke calls it the FA-031 U.S. Post Office Shoulder Pad but I call it the Godsend Shoulder Pad.